Hard to argue keeping a copy of some copyrighted work indefinitely counts as transient.
Precisely to argue for transient copies, they don't need to keep terabytes of data stored.
>Hard to argue keeping a copy of some copyrighted work indefinitely counts as transient.
You're assuming that they're keeping the works indefinitely, which again is not the case.
Those kinds of legal workarounds rarely work.
They are dependent persistent access allowing them the equivalent benefit of keeping a persistent copy.